Process of molding and vulcanizing tires.



J. COFFEY 64 J. H. COFFEY, JR. PROCESS OF MOLDING AND VULCANIZING TIRES.

APPLICATION FILED MAR-231 1915.

Patented Dec. 28, 1915.

' Corner and Josnrn HERBERT "snip srnrias or en- JOSEPH HERBERT COFFEYAND JOSEPH HERBERT COFFEY, JR., 01* TORONTO, ONTARIO, CANADA, ASSIGNORSF ENE-HALE TO GUT'IA PEROHA AND RUBBER, LIMITED, OF

TORONTO, CANADA.

PROCESS OF MOLDING AND VU'LCANIZING TIRES.

Specification of Letters Patent.

Application filed March 23, 1915. Serial No. 16,369.

ToaZZ whom c't may concern:

Be it known .that we, JOSEPH HERBERT orrnr, J r., of the city ofToronto, in the county of York, Province of @ntario, Canada, subjects ofthe King-of Great Britain, have invented certain new. and usefulImprovements in Processes of Molding and Vulcanizing Tires, of which thefollowing'is a specification. I I

In ordinary practice tires are vulcanized in molds either partial orcomplete, which renders 'it necessary in order to avoid too great anexpenditure for molds to reduce the time of curing as much as possible.Experience has shown that long curing is preferable to give durabilityto the tire, and our object is ,to devise a process of molding whichwillenable us to vulcanize in the open and thus give as much time as maybe'necessary for vulcanizing without tying up molds from-their properfunction in the shaping and forming'of tires. I

We attain our object by molding the tires on a suitable core and in asectional removable mold. The tread surface of the tire is tibn of themold being moved radially to compress the tire'against the tread portionof the core and draw thesides adjacent the tread toward the rim side. jacent the rimare pressed against the mold and stretched from the tread,the edges being also drawn away from the tread and inwardly toward eachother. The edges and the parts of the sides adjacent thereto are thenheld on the core whilethe-tread portion of the mold is removed radially.The sides are then'released and finally the tire is cured in a suitablevulcanizer either exposed or buried in powdered soapstone.

The process is carried out in detail sub stantially' as hereinafter morespecifically described and bymeans of apparatus such as illustrated inthe accompanying drawings in which Figure 1 is a sectional viewillustrating the first step in the process; Fig. 2 a similar viewshowing the second step; Fig. 3

. I a similar view showing the third step; Fig.

4 a similar wiew showing the fourth step;

v Fig. 5 a similar view showing the completely The sides 'adside of thetire.

of the side portions of the mold.

In the drawings like numerals of refer- Patented nee. as. rare.

ence indicate corresponding parts in the different figures.

In carrying out our process, the tire is first built up according toordinary methods on a suitable core 1, which may be of any ordinaryconstruction, though we. prefer to use the sectional core shown anddescribed in our Patent No. 1,15%,848, dated September 28, 1915, pressthe tread portion of the tire against the core and to draw the portionsof the side walls with the tire adjacent the tread toward the rim sideof the tire. Thisis effected by means of the tread moldsegments 2, whichare readily movable and so proportioned that the edges thereof willextend substantially to the middle of the side walls of the tire whenthe mold has been moved forward sufliciently to properly mold the treadof the tire. The next step' is to mold and compress the edges or beadsof the tire and the side-walls adjacent thereto. This is effected bymeans of the sectional side molds 3, which are moved not only toward theside walls, but at the same time away from the tread, the actualmovement being on a diagonal line inclined toward the rim To enable thismovement to be effectively performed, the adjacent sides of the sidemolds 8 and the tread mold 2 are cut 'as shown on a bevel. hen the tireis first formed, the edges thereof are somewhat closer to the treadportion of the tire than the corresponding portions of the side' moldsare to the tread portions of the mold, when the side molds and treadmolds are in the position shown in Fig. 4: with'the tire completelymolded. The consequence is that as the sidemolds are moved to positionpressing the side walls and edges of the tire against the core the edgesand side walls adjacentthereto are stretched and smoothly drawn aroundthe core. This completes the smoothing out and stretching of the sidewalls. which is commenced by the inward radial movement of the sectionsof the tread The next step is to com-.

mold. The purpose of this is to thoroughly stretch and smooth down thecanvasfabric of the tire-carcass so as to prevent wrinkles or bulgestherein, these wrinkles or bulges .35 moving the tread portion of themold rathe molded tire in any suitable manner.

being a fruitful-cause of blow-outs. After the side molds havebeen'm'oved up to complete the molding of the side Walls and the edges,they are securely retained in place in any suitable manner and the treadmold removed. The sides and edges of the tire being securely held, thetread mold comes away Without distorting the uncured tire.

After the tread mold has been removed, the.

side moldsare withdrawn. and removed.

It will be found that the tire owing to the I method of moldingemployed, 1s 1n suchcondition that it can then be easily cured in theopenin any suitable vulcanizer, the mold being then available vformolding another tire. In this way the molds may be employed all day inmolding tires, which may be subsequently'allowed to cure all night.

If the saving of molds is not a special consideration the tires might becured in the molds,.all the other advantages of our invention remaining.

As the tread portion of a mold is by farthe most expensive part, aconsiderable saving is effected even if the tires be cured with the sidemolds in place, and in some cases it may be desirable to retain them.The cores will usually be sectional, as integral cores can onlybe usedfor small sizes of tires owing to the difiiculty of removing them. v

What we claim as our invention is 1. A process of molding andvulcanizing tires which consists in molding the tire on a suitable coreand in a sectional mold, re-

dially while still holding the edges and the adjacent portions of thesides of the tire against .the core, then releasingthe sides and edgesof the tire, and finally vulcanizing manner.

3. A- process of molding and vulcanizing tires which consists in moldingthe tire on a core and in the process of molding stretching the sidesandedges in a direction away from the tread by pressure applied adjacentthe edges to displace said edges and increase the cross-sectional.circumference of the tire, and subsequently -vulcanizing the tire.

4. A process of molding-and vulcanizing tires which consists inpositioning the tire on a core; applying a molding pressure to the treadand part of the sidesof the tire in a direction normal to the tread;applying a molding and side-stretching pressure to the edges andportions of the sides adjacent thereto in a diagonal direction towardthe core to displace said edges and increase the cross-sectionalcircumference vof the inner periphery of the tire and subsequentlyvulcanizing the tire.

5. A process of molding and vnlcamzlng tires which conslsts 1n moldingthe tire on a core and 1n the process of moldlng stretching the sidesand edges in a direction awayfrom the tread by pressure applied ad acentthe edges, and subsequently removing the mold and vulcanizing the tire.

6. A process of molding and vulcanizing tires which consists inpositioning the tire on a core, applying a molding pressure to the treadand part of the sides of the tire in a direction normal to the tread,applying a molding and side stretching pressure to the edges andportions of the sides adjacent thereto in a diagonal direction towardthe core, and subsequently releasing and vulcaniz'ing the tire.

7. A nrocess of molding and vuleanizing tires which consists in moldingthe tire on a suitable core in a sectional. mold with ravdially movablesections, then removing the mold radially, and finally vnlcanizing thetire.

Signed at Toronto, Canada,'this 26th day of Feb., 1915, in the presenceof the two undersigned witnesses.

JOSEPH HERBERT COFEEY, JOSEPH HERBERT COFEEY, JUNIOR.

lVitnesseS J Eow. MAYBEE, H. M. CHRISTMAN.

